December 11, 2012

Y chromosome study of Italy (Brisighelli et al. 2012) incl. sample of Greek speakers from Salento

This is a wonderful new source of information on Y-chromosome variation in Italy, that also includes some samples of the linguistic minorities of Ladins and Griko speakers.

The latter is particularly interesting to me, because, these last Greeks of Magna Graecia are descended either from the ancient colonists or medieval Eastern Roman settlers, and as such may represent a group of Greek descendants that (i) may have admixed to some extent with local Italic speakers, but (ii) will not have had an opportunity to experience much post-medieval gene flow that may have affected Greeks from the Aegean.

There may be something wrong with the presentation of the haplogroup frequencies on the left; in particular, based on the text, I think that what appears as R1* is in fact R1*(xR1a1).

In any case, here are my observations on the Grecani Salentini sample:
  • They, as well as the Messapi, possess the highest frequencies of E-M78. This ties them to the Balkans in a very obvious way; this haplogroup was also interpreted as a signal of Greek colonization in Sicily and Massalia. This seems like the most obvious explanation; note that Salento is in Messapia, so the high frequency in the non-Greek denizens of the region may be simply the result of language shift, since the remaining Greek speakers are presumably the last remnant of a once much more numerous population that was linguistically Italicized as have most other Greek speaking populations of Italy and Sicily.
  • Their highest frequency haplogroups are R1*(xR1a1) and J2. Both are fairly common haplogroups in both Greece and Italy, so only a fine-scale analysis would be able to differentiate between what might be pre-Greek and what is Greek in origin. In any case, I have proposed that these two haplogroups were typical of (albeit not limited to) the Graeco-Phrygo-Armenian clade, so their occurrence in this sample is not surprising.
  • There is an occurrence of I*(xM26) chromosomes. This requires finer phylogenetic resolution, but certainly the absence of M26 -which has a SW European distribution- is interesting to note.
  • Haplogroup G-M201 again requires finer-scale resolution, and could be anything from a relative of the Neolithic Italians (having been found in the Tyrolean Iceman) to much more recent events.
  • Within haplogroup J, the majority of the chromosomes belong to clade J2, with about a tenth of the frequency made up of J*(xM62, M172). Note that these are not necessarily J*(xJ1,J2) as indicated in the figure, since M62 defines only a part of the J1 lineage.
  • The absence of haplogroup R1a1 in this sample is perhaps the most interesting finding. This occurs at a frequency of ~10% in Greek samples from Greece and is fairly variable. I have previously observed that it was absent in the south stream of Indo-European based on its paucity in Armenians, Albanians, and its uneven distribution in Greeks. Its absence in the Italian Griko sample reinforces this idea. A caveat, however, is that the origin of the Greek settlement of Italy can be traced to southern Greece and western Anatolia, so it's still possible that some R1a1 was present in other areas of the Aegean basin since pre-medieval times.
The authors of the paper use many conventional labels of what is "Neolithic" and what is not (e.g., R1*(xR1a1) is claimed as Mesolithic). But, certainly, both age estimation of modern chromosomes (e.g., Wei et al. 2012) and the ancient Y chromosome studies cast doubt on this association. I would say that rather than being predominantly pre-Neolithic, it might appear that the Y-chromosome gene pool of Italy may have been formed in late Neolithic to medieval times, with the only lineages that can convincingly trace their ancestry to the Neolithic or earlier epochs being G and I-M26.

As for the Ladins, the high frequency (67.7%) of R1*(xR1a1) is consistent with what I believe to have been the main Italo-Celtic lineage.

Finally, I should point out the occurrence of a couple of haplogroup L samples; this haplogroup is more typical of populations much to the east, being the "eastern" cousin of the more "western" haplogroup T within the LT clade. Certainly a finer-scale resolution of these two L samples might be informative about their potential origins and/or the ancient distribution of this rather mysterious haplogroup.


PLoS ONE 7(12): e50794. doi:10.1371/journal.pone.0050794

Uniparental Markers of Contemporary Italian Population Reveals Details on Its Pre-Roman Heritage

Francesca Brisighelli et al.

Abstract
Background

According to archaeological records and historical documentation, Italy has been a melting point for populations of different geographical and ethnic matrices. Although Italy has been a favorite subject for numerous population genetic studies, genetic patterns have never been analyzed comprehensively, including uniparental and autosomal markers throughout the country.

Methods/Principal Findings

A total of 583 individuals were sampled from across the Italian Peninsula, from ten distant (if homogeneous by language) ethnic communities — and from two linguistic isolates (Ladins, Grecani Salentini). All samples were first typed for the mitochondrial DNA (mtDNA) control region and selected coding region SNPs (mtSNPs). This data was pooled for analysis with 3,778 mtDNA control-region profiles collected from the literature. Secondly, a set of Y-chromosome SNPs and STRs were also analyzed in 479 individuals together with a panel of autosomal ancestry informative markers (AIMs) from 441 samples. The resulting genetic record reveals clines of genetic frequencies laid according to the latitude slant along continental Italy – probably generated by demographical events dating back to the Neolithic. The Ladins showed distinctive, if more recent structure. The Neolithic contribution was estimated for the Y-chromosome as 14.5% and for mtDNA as 10.5%. Y-chromosome data showed larger differentiation between North, Center and South than mtDNA. AIMs detected a minor sub-Saharan component; this is however higher than for other European non-Mediterranean populations. The same signal of sub-Saharan heritage was also evident in uniparental markers.

Conclusions/Significance

Italy shows patterns of molecular variation mirroring other European countries, although some heterogeneity exists based on different analysis and molecular markers. From North to South, Italy shows clinal patterns that were most likely modulated during Neolithic times.

Link

21 comments:

Ezr said...

Isn't much of R1a in Greece a result of Slavic invasions? Greek communities in Italy weren't affected by that (except maybe indirectly through new settlers).

jackson_montgomery_devoni said...

This is a very interesting study. We need more Y-DNA studies of Italy as Italy was such an important part of ancient and medieval Europe due to it's central Mediterranean location. It is interesting that you mention J2 as being part of the ''Graeco-Phyygo-Armenian'' clade as my own direct paternal line comes from Calabria and I am a J2 (J2a L26/L27 to be more precise). Some of my closest Y-STR matches have origins in Armenia. Mind you these are distant matches and we may not share a common ancestor at all within the last couple thousand years maybe. I know that STRs are notorious for faulty predictions now.

Onur said...

The AIM results do not make any sense. They show Italians, especially those in the south, more Mongoloid-admixed than all other Europeans, Germans and the Irish more Mongoloid-admixed than Slovenians, and the British more Negroid-admixed than all other non-Mediterranean Europeans (including the French), completely contradicting what we know about the European autosomal genetic landscape based on innumerable autosomal genetic studies. This is the result of using so few (only 52!) autosomal genetic markers. So we can not trust what they say on Negroid admixture in Italians. The AIM analysis is useless and should be ignored. The only useful part of the study is the uniparental analysis part.

mooreisbetter said...

Crazy timing. I just posted a blog post on the presence of I-M26 in the remote mountain regions of Southern Italy (Calabria). I hope the authors read your blog (and mine).

(Note to Dienekes: your post makes it sound like M26 was NOT found in Italy. The study shows significant M26 notably in Samnium ("Sanniti"), which is consistent with the theory that remote-located pre-Roman archaic Oscans bore M26. (In other words, it is aboriginal Italian as previously theorized). You might clarify your post.

My blog post is at:

http://snplogic.blogspot.com/2012/12/is-y-chromosome-haplogroup-m26-norman.html

aspromavro said...

GRSAL41 looks like I2 Dinaric S.

eurologist said...

The nomenclature is certainly messed up.

The main thing I get out of this paper is that the uniparental DNA is rather diverse in the south, and much less diverse and more typical non-east-Mediterranean Europe in the northeast.

Ponto said...

J-M62 is a typographical error. The SNP is a private SNP. It is obvious the researchers mean J-M267, the basal J1. Most of the early SNPs found in J1 are private.

Dienekes said...

(Note to Dienekes: your post makes it sound like M26 was NOT found in Italy. The study shows significant M26 notably in Samnium ("Sanniti"), which is consistent with the theory that remote-located pre-Roman archaic Oscans bore M26. (In other words, it is aboriginal Italian as previously theorized). You might clarify your post.


Read it again, my observations are for the Grecani Salentini.

South Central Haplo said...

"Finally, I should point out the occurrence of a couple of haplogroup L samples"

L major in Indus valley and T has lot of presence in nile delta.

Dienekes favourites:

J2 represents model Indo Aryan group.

My favourites:
.
1. J, L and T represent first urbanisation , agriculture communities in those parts.
2. R* got urbanized later

Not sure why Goat meat consumption is not popular in Italy and popular in Greece and Iran.

aspromavro said...

This VERY important find of one I2 Dinaric in Magna Graecia has just destroyed all fanciful theories promoted by panslavic ideologues on the internet (Mr "Magnus Ducatus")...so much for that...

bau said...

Hi, I come from Grecia Salentina, and as far I know, griko's speakers doesn't descend from Magna grecia colonization but from people moved in Salento during the iconoclastic period in VIII century.

AWood said...

Out of the 5 Greek hg I haplotypes, 2 are I1, and 2 I2b1c, and the final one is I2a2-Din. Despite the fact I2b1c is a Mediterranean branch, it's quite obvious it has roots in the regions of NW Europe. Perhaps 4 out of the 5 men are descended from Celtic settlers.

aspromavro said...

AWood, I-M223 is found in decent amounts in Anatolia. Phrygians (from Balkans) were maybe early carriers of y haplogroup I eastward to Anatolia.

http://archiver.rootsweb.ancestry.com/th/read/Y-DNA-HAPLOGROUP-I/2012-06/1340549170

Carlino Altoviti said...

The Greek language spoken in Salento is derived from the medieval greek , it has no connection with the Magna Grecia.

eurologist said...

bau and Carlino Altoviti,

Are you saying that those Greek speakers don't ultimately derive from Greece? I don't think so, and more importantly, much of that before Slavic (and Germanic-tainted) expansion.

SimonW said...

First of all, I'm glad about every new study on the genetic variation of Italy, so thanks to the authors.

However, I've got some critical remarks on the paper:

Before the Roman conquest, ancient Italy was characterized only by the presence of Indo-European populations [6] living in the Italian Peninsula since the second millennium BC, corresponding to the period between the Iron Age and Romanization [2].

Just a few paragraphs later there is this contradictory assertion:

At the time of the Roman Empire, at least two non-Indo-European populations still inhabited Italy, namely, the Ligures, in the northwestern area, and the Etruscans with settlements located in areas far from the Etruria (Tuscany and High Latium), such as the Po Plain and the coast of Campania.

Besides the obvious inconsistency, it has to be said that it is not at all clear that the Ligures were non-Indo-European - even though one often comes across this claim. There is not much textual evidence left from them, but it appears much more likely that their language was closely related to the Kelto-Italic branch of Indo-European.

Besides the already mentioned Terramare tribe, on the southern edge of the Po Valley, and the Villanovans, probably from Eastern Europe who settled throughout Central Italy, there were also the Umbrians to the east of the upper basin of the Tiber.

There is a lapse here: There was no Terramare tribe mentioned in the text before that sentence.

As for the Villanovans: It was the (final bronze age) Proto-Villanovan culture that had connections to "Eastern Europe", or more aptly said, to eastern central Europe, i.e. Hungary, Slovenia etc., the eastern branch of the central European urnfield culture. The Proto-Villanovan culture shouldn't be confused with the (iron age) Villanovan culture, as the former was spread across the entire Italian peninsula, while the latter had a much more restricted distribution.

SimonW said...

The Veneti, who occupied the territory that still bears their name, originally came from Illyria as did the Messapii (now modern Salento or South Apulia) and Iapyges, who settled in present-day Puglia (Apulia) [5].

The Venetic language afaik is no longer considered Illyrian. It's close to Italic, to Latino-Faliscan in particular, but has also got some Germanic affinities. (Little is known about Illyrian, but it has been suggested that it has connections to Italo-Keltic, too.) Personally I presume that the ethnogenesis of the Veneti involved an eastern element, stemming from Paphlagonia, as reported in the ancient sources; this would explain the occurence of J2 (and maybe also the Raetic language in the eastern Alps, which was a relative of Etruscan and Lemnian). The Venetic language however probably came from central Europe, presumably from the Danube valley, and was related to the arrival of the Liburnians.

This culture [the Cardium pottery] entered from Greece towards the South-Center of Italy through the Adriatic Sea, carried by the same farmers that introduced, for instance, Y-chromosome haplogroup J2 at about the same frequency in Central and South Italy, but with lower introgression into the North; from here followed further Mediterranean expansions towards Iberia.

We now have got ancient y-DNA from the Epicardial culture of Catalonia (Avellaner cave), from the post-Casséen Languedoc (Treilles) and from the about contemporaneous Italian Alps (Ötzi). All of these were ultimately Cardium derived. And there is only one haplogroup that predominates there: it's G2a. No trace of J2 has been found. Small percentages of E-V13 and I2a accompanied the G instead. So the evidence points to a G2a dominated Cardium pottery.

Finally, I have to say that in the map with the sites of the samples, Ancona looks very offish, that far north from the Conero, where it is actually situated! It may appear like nit picking, but because of this it is unclear where the Picenes sample was collected. North of the Conerco? Or south of Ancona? In the map ist's both... The ancient tribe of the Picentes actually lived only south of the Esino.

Now for a comment by Dienekes:

As for the Ladins, the high frequency (67.7%) of R1*(xR1a1) is consistent with what I believe to have been the main Italo-Celtic lineage.

But the Ladins live more or less in the centre of the ancient Raetic world. Well, presumably there was a strong Keltic, or more likely, even Ligurian substrate. Anyway, ultimately this central European R1b appears Bell Beaker derived, which in my opinion would make it rather Basque related. The Italics and Kelts became strongly associated with it as soon as they entered central Europe...

Carlino Altoviti said...

@eurologist

What I know is that the language called "Griko" spoken in some towns in Salento is derivated from the medieval greek language, not from the ancient greek. It must therefore be assumed that it is related to emigration during the "iconoclastic" time, under the imperor LIon III, when we know that persecution drove many Greeks to cross the sea.

Carlino Altoviti said...

Sorry, VII century A.D.

Marky said...

Is this one of the subjects being tackled if I get to study in italy?

jepaspeur said...

@Personally I presume that the ethnogenesis of the Veneti involved an eastern element, stemming from Paphlagonia, as reported in the ancient sources...

NO, I disagree. If the Veneti traveled, doesn't mean they were mixed with people from Anatolia. It's just a theory without evidences because we modern Venetians are nothing else than every other European.